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YOU CAN 3D PRINT THIS POCKET ROBOT THAT BLINKS, TALKS AND FOLLOWS YOUR FACE

A palm-sized robot that blinks, breathes and follows your face — community-built since 2021, now with M5Stack hardware support.

by meganetaaan (Shinya Ishikawa)

FULL CAD BOM FIRMWARE DOCS

RoboticsAI

Built with3D printing

difficulty
●●●○○
time
a weekend-plus
license
Apache-2.0
repo
repo ACTIVE1,746 stars

WHAT YOU’LL NEED

Videos
1
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COMPAREE VERDICT

Stack-chan is a genuinely charming desktop robot: an animated face on the M5Stack screen blinks and talks, and two servos pan and tilt the head to follow you. The hardware is simple — an M5Stack controller, a small servo board, two servos and a 3D-printed shell — but the character comes from the JavaScript firmware, which has had years of community polish. The single hardest part is setting up the servos: mount them at the wrong reference angle and the head binds against the case. The repository contains the firmware, STL and STEP files, a case guide with parts and print orientation, and board schematics; the Discord fills in the rest. If you have printed articulated models before, this is a weekend project; if you have not, plan for a second weekend. M5Stack now sells a preassembled M5StackChan, but the open-source version is still the one you can modify — and that is the entire reason to build it.

GOOD TO KNOW

  • —STL files, firmware and assembly instructions are all in the repository.
  • —The DIY build uses an M5Stack core plus a small Stack-chan servo board; schematics and board layouts are in the repository.
  • —Documentation is in Japanese and English, with community translations.
  • —The case guide shows the recommended print orientation; filament and infill are left to you.
  • —Licensed under Apache 2.0: you can build commercially, but attribution is required.
  • —M5Stack sells a preassembled M5StackChan with its own factory firmware; the open firmware from the repo is free and can be flashed onto it from the browser.

Parts to buy

7 items

From our check of the build. Exact quantities and part numbers are in the creator’s BOM.

  • Either a preassembled M5StackChanFind
  • For DIY: an M5Stack CoreFind
  • Stack-chan servo boardFind
  • Two servos (SG90, SCS0009 or RS30X)Find
  • Small 3.7 V LiPo batteryFind
  • M2 screwsFind
  • USB-C data cableFind

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Can I build this?

PrintShell, feet, bracket and battery backpack (STL and STEP in the repository)
BuyEither a preassembled M5StackChan (K151, 99 dollars in the M5Stack store), or for DIY: an M5Stack Core (Basic/Gray/Go/Fire per the case guide), the Stack-chan servo board, two servos (SG90, SCS0009 or RS30X), a small 3.7 V LiPo battery, M2 screws, USB-C data cable
Tools3D printer, screwdriver, soldering iron if you modify wiring
SkillsBasic 3D printing, flashing firmware from the browser (JavaScript/Moddable SDK if you modify it), servo setup (the hard part)
TimeOne weekend for the build, a second if servo tuning goes wrong
Cost$$, dominated by the M5Stack module
SafetyLow voltage, but not risk-free: the project warns that SG90 servos can get very hot and even smoke if overloaded, for example when the head is driven past its physical limits, so check servo angles before fixing them in the case and do not twist the head while the servos hold torque. The DIY build uses a small 3.7 V LiPo battery; treat it with normal lithium-cell care.

Build at your own risk. Projects involve tools, electronics and sometimes mains voltage — follow the creator’s safety notes.

Videos

Stack-chan: the open communication robot for everyone

The project's official introduction video, linked from the README (English subtitles).

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Gallery

repository-images.githubusercontent.com

Start here

Navigation into the creator’s own docs — we don’t rewrite the guide, we route you to the source.

  1. 1.Read the English README and check the hardware compatibility list (Confirm your M5Stack board is supported before ordering anything.)
  2. 2.Print the shell, feet, bracket and battery backpack(STL and STEP files are in the case folder for SG90, SCS0009 and RS30X servos; follow the recommended print orientation shown in the case README.)
  3. 3.Flash the firmware and calibrate the servos(Flash from the browser with the official Web firmware installer (Chrome or Edge) — no toolchain needed. Building from source uses the Moddable SDK. Servo setup is the step that takes longest.)

Resources

Documentation, files and community threads for this build — we link straight to the original sources and never rehost the creator’s files.

KNOWN ISSUES

  • Buying the wrong M5Stack module. The firmware supports M5Stack (Basic/Gray/Fire), Core2 and CoreS3; the preassembled M5StackChan CoreS3 is the reference target. ATOMS3 is not on the list.
  • Servo choice. SG90 servos are cheap, but the project notes they are hard to move smoothly and their inrush current can occasionally reset the M5Stack. Serial servos (SCS0009 or RS30X) cost more but allow speed control and reading the head position.
  • Servo mounting angle. Each servo must be installed at its reference angle (SG90 at 90 degrees, SCS0009 at 100, RS30X at 0); the case guide warns that a servo mounted the wrong way interferes with the housing, and recommends flashing the firmware and checking servo motion before fixing them in the case.
  • Flashing the open firmware replaces M5Stack's factory firmware on an M5StackChan. Keep the M5Burner restore procedure handy if you want to go back.
  • The servo board is the gap. The case guide lists the printed parts, servos, battery and screws with shop links, but the board's parts list is marked under construction and the manufacturing files are announced as links to be added, so check the repo and Discord for the current board files before ordering.
  • Japanese-first documentation. The English README is good, but deeper guides and community troubleshooting are often in Japanese first, then translated.

Can I build this without the M5Stack Kickstarter kit?

Yes. The Apache-licensed repository has the firmware, the browser tools, STL and STEP case files for three servo types and the board schematics; the case guide lists the parts. The one gap is the servo board: its manufacturing files are still marked as links to be added, so check the repo or Discord before ordering.

What is the difference between the M5Stack boards?

The distributed firmware supports the original M5Stack, Core2, CoreS3 and the preassembled M5StackChan CoreS3. The M5StackChan CoreS3 is the standard configuration and the one the developers validate releases on physical hardware with.

Do I need to solder anything?

Not with the preassembled M5StackChan. For the DIY build, the servos and battery plug into the Stack-chan servo board; the board itself uses SMD parts, and the project suggests ordering it assembled from a PCB manufacturer such as JLCPCB.

How do I stop the servos juddering?

The project itself says SG90 servos are difficult to move smoothly. If smooth motion matters, use the supported serial servos (SCS0009 or RS30X), which allow speed limits, and make sure each servo is mounted at its reference angle so the head does not bind.

Community builds

No community builds yet — be the first, we feature the best ones.

Discussion1

FROM THE COMPAREE TEAM

The firmware has had years of community polish — smooth blinking, breathing animations, face tracking that actually works. If you have built one, what was the single tweak that made the biggest difference?

CompareeTEAM2mo agoedited

Practical notes from our verification: the repository is active and documented in both Japanese and English. The easiest start is not a full DIY build: the README recommends a preassembled M5StackChan from M5Stack plus the browser-based firmware installer, which needs no Moddable SDK or ESP-IDF — the firmware is JavaScript-driven, and flashing it replaces M5Stack's factory firmware (a restore procedure is documented). If you want to build the hardware yourself, the case guide covers parts and assembly, the printable cases come as STL and STEP for SG90, SCS0009 and RS30X servos, the case README shows the recommended print orientation, and schematics and board files are in the repo too. The README links an official video with English subtitles, and there is a Discord server for questions. Correction (4 October 2026): we re-checked this page line by line against the project's own repository, documentation and videos, and fixed errors in earlier versions.

meganetaaan (Shinya Ishikawa)

Shinya Ishikawa started Stack-chan as an open-source project in 2021. A community grew around it, with makers contributing cases, boards and AI features, and in January 2026 M5Stack launched a preassembled StackChan on Kickstarter, co-created with that community.

GitHub

Star the project on GitHub

DISCLAIMER

  • Comparee is not the author of the projects featured here. All rights to each project belong to its creator — every page links to the original source, and we never host creators’ files.
  • Information is provided without warranty and may become outdated as projects evolve. Prices are indicative bands only — always check the creator’s parts list for current costs.
  • Building and operating any project is at your own responsibility. Protective equipment, safe workshop practice and compliance with local regulations are the builder’s responsibility.
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